As a windshield wiper motor of this type, there is a motor known such that, by providing the number of motor poles (field portions) as four or more poles for the multipolarity, magnetic saturation in a yoke is reduced and torque is improved with improvement of an operating point, and the motor can be sized down (see, for example, Japanese Patent Application Laid-Open Publication No. 2007-143278 (FIGS. 2 and 3)).